Abstract: This invention relates to a glass reflector and tungsten-halogen lamp combination wherein the lamp is cemented into the glass reflector with an aluminum phosphate cement composition which comprise a mixture of aluminum phosphate containing excess phosphoric acid, relatively small particle size alumina and a mixture of relatively medium and coarse particle size inert filler materials and wherein the lamp contains a hermetic seal between quartz and a molybdenum foil with that portion of the foil in the seal area which is exposed to an oxidizing environment coated with alkali metal silicate.